Proxmox Virtual Environment

iSCSI

Basics

Initiator name is stored in /etc/iscsi/initiatorname.iscsi.

Change some default values in /etc/iscsi/iscsid.conf:

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# old value: 120 new value: 15
node.session.timeo.replacement_timeout = 15

Add the iSCSI LUN via Proxmox VE GUI:

1. Navigate to the Datacenter view.
2. Select the storage where you want to add the iSCSI LUN.
3. Click on "Add" and then "iSCSI".
4. Fill in the required fields, including the iSCSI target information.

iSCSI Multipath

Proxmox does not preinstall multipath-tools, so it have to be installed manually:

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apt update
apt install multipath-tools

Add /etc/multipath.conf configuration file - try to get information about SAN from vendor to set correct values. Following example is for DELL ME4024 SAN

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##Default System Values
defaults {
   user_friendly_names yes
   find_multipaths strict
   max_fds 8192
   polling_interval 5
   queue_without_daemon no
}

## Universal Blacklist  (recommend white-listing)
blacklist {
   device {
      vendor '*'
      product '*'
   }
}

## Blacklist Exceptions
blacklist_exceptions {
   device {
      vendor "DellEMC"
      product "ME4"
   }
}

## Dell Device Configuration
devices {
   device {
      vendor "DellEMC"
      product "ME4"
      path_grouping_policy group_by_prio
      path_checker "tur"
      hardware_handler "1 alua"
      prio "alua"
      failback immediate
      rr_weight "uniform"
      path_selector "service-time 0"
   }
}

To identify the iSCSI LUNs, use the WWID. The command scsi_id can be used to determine the WWID of a device:

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/lib/udev/scsi_id -g -u -d /dev/sdX

Replace /dev/sdX with the appropriate device identifier, which you can get with following command:

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iscsiadm -m session -P3

Add WWIDs to the WWIDs file

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multipath -a <WWID>

Increase size of VG

1. Enlarge LUN on SAN
2. Get involved iSCSI devices

   1	multipath -ll

3. Rescan the iSCSI devices - replace sdX with involved device names and repeat it for every device

   1	echo 1 > /sys/block/sdX/device/rescan

4. Check size before increasing for comparison

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   multipath -l /dev/sdX # or multipath -l /dev/mapper/mpathX

5. Resize multipath device

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   multipathd resize map mpathX # reload multipath multipath -r

6. Check size after resizing

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   multipath -l /dev/sdX # or multipath -l /dev/mapper/mpathX # or lsblk /dev/mapper/mpathX

7. Resize of physical volume

   1	pvresize /dev/mapper/mpathX

Add unreferenced disks back to VM

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qm rescan --vmid XXX

When this operation fails, check whether the disk is an LVM volume and whether it is deactivated, and if so, activate it.

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lvdisplay | grep XXX

When disk is deactivated - get LV Path from above command and activate it:

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lvchange -ay /dev/me4-sas-01/vm-122-disk-0.qcow2

Repeat the rescan for the VM

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qm rescan --vmid XXX